Process of making sulfur dyes.



No Drawing.

To all whom it may concern Be it known that I, ERNST Vonrrnn, chemist, asubject of the King of Wurttemberg, residing at 2 Markt, Bockum, nearCrefeld, Kingdom of Prussia,-German Empire,have invented new and usefulIm rovements in Processes of Making Sulfur yes, of which the followingis a specification.

This invention relates to the manufacture of sulfur dyes.

Specification of Letters Batent.

It has been observed, that a large number ofprecipitated sulfur dyes,when treated with the suitable quantity of sulfid of sodium areconverted into new. compounds in which free sulfid of alkali cannot bedetected; for example they do not blacken polished silver plate.Therefore only such amounts of sulfid are added as can enter intochemical combination with the sulfur dyes. This quantity of sulfidisinsuflicient for producing the liquid state and the dyes totallyundissolved.

Most of the sulfur dyes are suitable for this process, especially thedyestuffs of diphenylamin, indophenols, m-diamins and generallyderivatives and substitution products of the named groups. As chieflysuitable for carrying out my process I have found for instance thevarious brandsv of the following sulfur dyes in precipitated state:-auronal-black, sulfur-black (Actiengesellschaft fiirAnilinfabrikation, Berlin),

remaln P,

thiophenol-black (Gesellschaft F'fiir. Chemische Industrie in Basel),i-mmedial-black, katigen-black, Vidal-black, immedialindon,iruronal-green, katigen-brown, auronal-yelow.

It is evident, that instead of the dry dyestufls the pressed cakes inwet state may also be used.

The conditions for carrying out the reacv tion may vary and will beascertained in the special cases by those skilled in'the art by ,meansof experiments. Generally a rise of temperature and an evolution of"ammonia will take place,

The new sulfur dyes have not, only an 1n- Kcreased dyeing power butdissolve more easily, requlring, therefore, a considerably smallerquantity of sulfid of sodium and dye more evenly than the parentcompounds. Of still greater importance is however theunexpected'property of my new sulfur dyes with sulfur dyes.

ERNST von'r'rnn, or BOCKUM, NEAR GREFELD, GERMANY.

PROCESS OF MAKING SULIiUR DYES.

. Patented Oct. 3, 1916. Application filed February 26, 1907. Serial No.359,529.

that they do not blacken, when combined w1th diluted caustic alkal is oralkaline salts and the usual additions, the copper printing rollers. Onaccount of this property the new sulfur dyes are particularly adaptedfor printing. The production of the new dye-stuffs is very simple andcheap so that the new sulfur dyes show a considerable technical'progressin i The new sulfur dyes are decomposedby means of acids andconcentrated solutions of caustic alkalis mostly at an ordinarytemperature, giving then the well known reaction printing and dyeing ofsulfids, for instance blackening leadp'aper, whereas diluted solutionsof caustic alkalis and alkaline salts, as for instance carbonate ofsoda, cause the said decomposition only ata relatively high temperatureas used in the steaming process. The said formation of sulfid ofalkali'during the steaming process is probably the reason forthefixation of the'new dyes. By the addition of sulfur to the new dyes the.intensit and fastness of the colors may be increase The new dyes may beprepared in the following manner: 100 parts of sulfur-black T extraconcentrated (preparedby the'Actiengesellschaft fiir Anilinfabrikationaccording to United States Patent N 0. 655,659 by boiling dinitrophenol(4:2:1) with polysulfid of sodium and precipitating the dyestufl) aremixed with a concentrated solution of 30-35 parts ofsulfid of sodiumuntil a uniform mixture is obtained. With the development of ammonia thetemperature rises, the volume of the dyes being at the same timeincreased; some time afterward the presence of alkaline sulfid cannot bedetected by the usual reactions, 2'. e. aeopper or silver plate will notbeblackened, be-

' cause the sulfid of alkali, producing .with the above metals blacksulfur compounds,

ing operationthe cc lor paste is mixed with the usual .additionsfforinstance. 200 parts burnt starch and diluted solutions of causticalkalis or a salt of alkaline reaction, for lnstance 120 parts carbonateof sodium, and

the whole brought with the necessary quan pass a viscosimeter.

tity of water to 100 par ts; after printing 1. Process for making sulfurdyes in the form of pastes which consists in adding alkaline sulfidtoprecipitated sulfur dyes in such amounts that it will all combinechemi'cally with the said.dye,'leaving no uncombined or free alkalinesulfid. I

- 2." Pastes of sulfur dyes derived from isolatigli sulfur dyes byadding to them alkaline I in such amounts thatitwill all combinechemically with said dyes, the new dyes being undecomposed vby water,diluted caustic alkalis or alkaline salts atordinary temmoopee perature,leaving metals unblackened even in the presence of caustic alkalis oralkaline salts at ordinary temperature, but being decomposed by acidsunder evolution of sulfureted hydro-gen, being also decomposed ifprinted on textile fibers in admixture with caustic alkalis or alkalinesalts, by the action of steam under simultaneous fixation of the dye onthe fiber and rea pearance of free uncombined alkaline sulfi y Inwitness whereof I have hereunto signed my name this 13th day ofFebruary, 1907, in the presenceof two subscribing witnesses.

ERNST vonrrnn.

Witnesses MAR ARET WALLAQE, W. BRUCE WALLACE.

